html,
body {
    height: 100%;
}

body {
    display: flex;
    justify-content: center;
    align-items: center;
    margin: 0;
    overflow-y: hidden;
}

#paper {
    margin: 0 auto;
}

.joint-tool[data-tool-name="button"] circle {
    fill: #333;
}

.joint-tool[data-tool-name="connect"]:not(:hover) {
    opacity: 0;
}

.active [joint-selector="line"] {
    stroke: #4666E5;
}
